This invention relates to bird feeders for foiling squirrels and other rodents. It has been a problem to provide bird feeders which are not disturbed by squirrels. Squirrels and other predators are constantly endeavoring to climb upon the bird feeder and not only drive away the birds, but also feed on the seed and scatter seed with consequent loss.
One method of protecting the dish from squirrels is disclosed in U.S. Pat. No. 4,030,451 and U.S. Pat. No. 4,102,308. These feeders are constructed by having a semi-cylindrical hood connected to a dish that is mounted below. The hood covers a feed dish to protect the seed from the rain and from rodents. Drawbacks to this dish is that it does not hold a large quantity of seed, consequently the seed dish requires constant replenishment. Further, when the squirrel attempts to land on these feeders, or when the wind blows, the feeder swings to the side, which may result in spillage of the seed.
Other feeders that provide protection against theft of bird seed are disclosed in U.S. Pat. Nos. 3,590,780, 3,482,549 and 4,821,681. These patents disclose springs and tubular guards to prevent access by rodents. These devices complicate the manufacturing of these feeders. Thus, these feeders have parts that can break down thereby requiring repair and maintenance.
Another feeder used to present squirrels from accessing seed is disclosed in U.S. Pat. No. 3,977,363. This feeder has a detachable roof with a steep pitch and with lower eaves having a gentle pitch. The roof pitch dumps the squirrel when it climbs on the roof. A drawback to this feeder is that when the squirrel attempts to access the seed the bird feeder may swing and tip, resulting in seed being spilled. In cold weather conditions, ice may become trapped between the gentle pitch and the steeper pitch of the roof resulting in the roof cracking. Another drawback to this device is that it does not provide for 360.degree. perching by the birds. This feeder only provides a limited number of perches connected to the bottom of the housing. This bird feeder also uses ropes and strings to hold the roof to the feeder. These ropes may wear out in time, thereby requiring replacement. The perimeter of the feeder tray in this device is close to the outer edge of the cover. Consequently, when the feeder swings the squirrels may be able to jump onto the feeder and access the feed tray.